1. Field of the Invention
The present invention relates to a method for sealing a puncture wound in a blood vessel and a device for practicing said method.
2. Related Background
In certain medical procedures, such as cardiac catheterization, dilatation and counterpulsatlon, a catheter or other device is inserted into an artery, most commonly by percutaneous methods, and then fed through the arterial tree to the site where needed, frequently, the region of the heart. The site usually selected for insertion is the groin, because the femoral artery in that region is relatively easy to locate.
These procedures are normally initiated by insertion of an angiographic needle, followed by passing a guide wire through that needle into the artery. The needle is then removed leaving the guide wire in place. Next, a sheath-dilator set is passed over the guide wire into the artery in order to enlarge the opening sufficiently to permit entry of the catheter or other device. The dilator is then removed, leaving the sheath or guide cannula in place. The catheter or other device can then be inserted through the cannula with full confidence that when it emerges from the distal end it will be within the lumen of the artery.
It should be understood that the subject invention is independent of the nature of the medical device being used to treat the patient. Accordingly, the term "catheter" will be used here in a very generic and broad way to include not only "catheters" in the strict sense, but any device that is inserted into a blood vessel of the body.
Similarly, the subject invention is independent of the blood vessel involved. While it is anticipated that the femoral artery will be the most commonly used blood vessel, other arteries as well as veins might just as easily be involved.
After a procedure, for example, counterpulsation, has been completed, the sheath must be removed and the wound closed. Often, this can be accomplished simply by the application of digital pressure, generally augmented by the use of a pressure dressing. Customarily, pressure must be applied for at least 1/2 hour, and frequently for much longer than that. While pressure dressings often suffice, it is not uncommon for additional devices, such as sandbags, to be needed. In addition, during this period the patient must be immobilized, lest movement interfere with the closing process. Because of the pressure required, the time during which it must be applied and the need for immobilization, the procedure is painful and uncomfortable. It also requires prolonged personal attention of a health care professional. Finally, wound closures accomplished in this manner are prone to reopen unexpectedly long after closure appears to have been completed. Patients are therefore often required to remain in the hospital for 24 hours or longer.
Because sealing can be such a problem, cardiologists tend to use the smallest calibre catheters when performing catheterization procedures. Larger calibre catheters, however, are far preferable. An improved sealing procedure whereby larger catheters can be used without increasing the sealing difficulties would greatly facilitate cardiac catheterization.
A series of related devices which were designed to address some of these problems is described in U.S. Pat. Nos. 4,744,364, 4,852,568 and 4,890,612. These three patents describe a mushroom or umbrella shaped device which is used to seal the artery from the inside. The head of the device is placed within the arterial lumen and means are provided to pull and hold the underside of the head against the inside wall of the lumen. It is believed, however, that sealing from the inside can be the source of its own problems, including the promotion of clot formation inside the vessel.
Another method for sealing a puncture wound is described in U.S. Pat. No. 4,929,246. The approach taken there is to insert a balloon-tipped catheter into the tissue wound, inflate the balloon against the hole in the artery and then use a laser to thermally weld the wound closed.
The present invention is believed to overcome most of the drawbacks of the traditional method, without creating any new difficulties. This is accomplished by using a plug, preferably a collagen plug or plug of some other resorbable material, to seal the artery along its outside wall.